The present invention relates to a hand-held, self-powered, automatically regulated inflator primarily for bicycle tires, delivering low volume at high pressure, and more particularly for maintaining correct air pressure in bicycle tires.
Although the present invention is hereinafter discussed as to its use for the filling of bicycle tires, it is appreciated that other items that require air under pressure to be inflated to a selected predetermined pressure may also be filled using the device of the present invention.
Bicycle owners face a common problem, that of keeping their tires properly inflated. All bicycle tires lose pressure constantly. A few days of storage results in pressure loss to the danger point. And the rate of pressure loss is much greater while riding. As every bicycle rider knows, the loss of even a few pounds pressure vastly increases the effort required to pedal the bicycle, reduces controllability, and results in short tread life and early destruction of the tires.
Over the years the mechanical components of bicycles have been vastly improved. Lightweight alloy steel frames, multiple speed chain drives, two wheel brakes. All of these make for bicycles that are easier to ride, more adaptable to varying terrain, and safer. But the basic problem of tire inflation remains unresolved. If anything, it has gotten more acute. This is due to the ever-increasing popularity of the narrow, high pressure tires used on the more sophisticated bicycles. In the earlier days of bicycling, these high pressure tires were a comparative rarity, used only by professionals on very expensive competition bicycles. This is no longer the case. Now almost every rider deeply involved in the sport insists upon owning one or more bicycles equipped with these high performance, high pressure tires.
There are two means of bicycle tire inflation commonly used. One is the automobile tire inflation hose found at filling stations. Not only is the source inconvenient, it may force the bicycle owner to "walk" his bicycle many blocks on soft tires to reach it. But it very often results in a classic example of "overkill." A split second's delay in removing the air chuck from the tire valve, and the tire is destroyed in one ear-splitting sound.
The other method in use is the hand pump. This method is safe, but physically demanding. In fact, it is considered so onerous a task that often bicycle owners will deliberately ride on soft, underinflated tires rather than go through the sweating, hand-blistering job of pumping them up to correct pressure.
As an example, the standard type of "tire pump" has a cylinder of 11/4 inches diameter. To reach an inflation pressure of 110 lbs. sq. in., which is demanded by the popular "racing type" tire, a force of 135 lbs. is required on the pump handle.
The telescopic type pump often found around bicyclists is slightly better, but not much. Unless the user has heavily calloused palms and arms of steel, he will very soon tire of this exertion. This procedure of pressure checking and reinflation is to be gone through every time the bicycle is to be used. Obviously, this is beyond the physical capabilities of children and the elderly. And these groups comprise a large sector of bicycle users.